(19)

(11)

EP 1 999 834 A2

(12)

(88) Date of publication A3: 27.12.2007 (43) Date of publication: 10.12.2008 Bulletin 2008/50 (21) Application number: 07752612.7 (22) Date of filing: 07.03.2007

(51) International Patent Classification (IPC):  H02J 3/00(2006.01) (86) International application number: PCT/US2007/005925 (87) International publication number: WO 2007/103498 (13.09.2007 Gazette 2007/37)

(84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC MT NL PL PT RO SE SI SK TR (30) Priority: 07.03.2006 US 779845 P 08.03.2006 US 780136 P 06.03.2007 US 714647 (71) Applicant: Siemens Power Transmission & Distribution, Inc. Raleigh, NC 27609 (US)	(72) Inventor: CHEN, Dingguo Eden Prairie, Minnesota 55347 (US) (74) Representative: Morgan, Marc  Siemens AG, Postfach 22 16 34 80506 Munich 80506 Munich (DE)